A wind power generation system utilizing a windmill is generally provided with: a windmill body for receiving a wind and generating torque; and a generator for generating electric power by means of the torque generated in the windmill body. In such a windmill, there is a possibility that appropriate charging cannot be performed depending upon whether a wind is heavy or gentle. Therefore, in Patent Document 1 or the like, a power line for transmitting an alternating current output of a generator is connected to a battery via a controller which is a power management device for performing power management.
The controller performs power management such as circuit switching according to power at the time of rectifying an alternating current output of the generator and performing battery charging or power management at the time of supplying power to an alternating current load via an inverter. At this time, controls are effected such that: rotation count information taken out from the windmill via a rotational speed detector which is a mechanical detecting unit is inputted via an input line; damping is applied at the time of over-rotation in a controller; a clutch is provided at a position at which the windmill's generator is disconnected from windmill body's rotary shaft so as to disconnect the clutch at the time of a gentle wind; and ON/OFF is switched for a battery charge circuit. Such a controller is generally commercially available as a discrete device.
[Patent Document 1] Japanese Patent Application Laid-open No. 2005-130651